Pneumatic displacement pump



Ffilea Nov. 22, 1921 J ,L LATTA PNEUMATIG DISPLAGEMENT PUMP May 5, 1925.

Patented May 5, 1925.

JOHN L. LATTA, or HICKORY, NORTH CAROLINA.

PNEUMATIC DISPLACEMENT PUMP.

Application filed November 22, 1921. Serial No. 516,944.

j yTo all wh-omit may concern.'

Be it known that I, JOHN L. LATTA, a citizen of the i United States, residing at Hickory, in the county ofv Catawba and State of North Carolina, have invented certain new and useful Improvements inV Pneumatic Displacement Pumps, of which the following is a specification.

`The present invention relates to pneu matic displacement pumps, and particularly to an improvement of the pumpl disclosed in my U. S. Patent No. 1,237,530, granted August 21, 1917. j'

An object of the present invention is to improve the said type of pump, first, by the provision of an improved valve ci greater efficiency and utility; second, by the pro vision of means whereby sand and grit are kept from `injuring the cylinder and piston leathers of the pump; and third, by the provision of a different arrangement of the reliet conduit, whereby the discharge there- `from does not` agitate the water near the intake of the pump. ,Y l Y Other objects and advantages ot the invention will appear from the following speciiication in connection with the accompanying drawings, wherein Figure 1 is a central longitudinal section of the pump, a few portions being shown in elevation; i v

`Figure 2 is an enlarged representationv of a part of the structure shownin Figure 1 vand illustrating the valve and pistonV structure in section; and y 4 Figure 3 is a cross-section of the pump .on the line 3-3 of` Figure 1Q i Y Y The device comprises an outer casing 1, a head 2 removably secured to and closing the top of said casing, and a cap 3 similarlyremovably secured to and closing the bottom et may be interposed' at the joints to make them fluid-tight. rods 69 and nuts 70 are provided to secure the head 2 and cap 3 to the casing 1.` Y A foot valve 5 consisting of a disk of `metal 6 having a disk 7 `O semi-.hard rubber or other suitable packing material secured thereto, cooperates with a seat 8 in the cap 3. Valve retainers 9 are provided to keep the valve 5 properly positioned, in the usual way. The valve structure just described acts as a check valve, to enter and automatically closing against return of the said water.A

In the casing 1.is arrangedthe cylinder Stay "for said conduit.

opening-to allow the waterV 10 which terminates at its top in ahead 11, and at its bottomin a head 25 which carries a piston 12 from which projects a rod 13 carrying a valveV disk 14 made of rubber or the like, secured thereto bya nut 15 and washer 16. The piston 12 is provided with a pair of cup leathers 17 working in a dash pot cylinder` 18. Above the leathers 17 is a felt washer 19. VThe piston comprises the washers 20 and 21 and the hollow nut 22, as well as the leathers 17. The said hollownut 22 is provided with apertures 23 and is secured to one end of a tubular stem 24,-, .the other end of whichris secured to the lower head 25 of cylinder 10, which thus serves tov clamp the piston in place. The cylinder 10, somewhat below its top, is provided with a series of apertures 26, and near its bottom is provided with a similar series of apertures 27. The top tace of the lower head 25 serves as a valve .seat,cooperating` with a peculiarly shaped1 valve member 28, hereinafter reerred toas the billet, which is described` in detail elsewhere in this specification. A tubular conduit 29 is mounted in a recess 3() 4Figure 1. Conduit 29 communicates through bore 54` with an air exhaust conduit 55, as shown. A helical spring 31 encircles the conduit 29 and is secured at its upper end to Vin the upper head2 of the casing 1 and piohead 11, the spring being of such length that its lower end is substantially aligned with the .lower end of conduit 29 whenthe cylinder 10 is in its raised position. Helical springs 32 areprovided, andsecured at their upper ends to eyelets 33, their lower ends being secured to the cylinder 10 by fastening means 34, these springs ,being 'of such strength that they lift the cylinder and its connected parts toits upper position except when otherforces overcome them during "theoperation of the device. A seat 35 is provided at the lower end of the conduit 129, and a spherical valve 6,7` cooperates therewith to act as a. closure j 'This spherical valve is buoyant, that is, liquid-to be yhandled by the pump.

The billet 28 consists of a core 36 of wood .or other material, covered with soft rubber 37, and having embeddedtherein a metallic guide'member 38, which terminates in an of less density than the inverted cone 39 serving to aid the billet in seating properly. The core is of such nature that the whole billet preferably is of a density slightly less than that of the liquid handled by the pump, so that it will just iioat, and the weight of the materials is so distributed that it will float in upright position even without the guidance of the cylinder 10, thus assisting in the readiness of response of said billet to the level of the liquid in the cylinder and diminishing friction between billet and-cylinder. While wood is a cheap, convenient, and satisfactory material for the core, obviously a hollow metal or other core of equal buoyancy may serve equally well, and the core may even be omitted entirely if the rubber portion is correspondingly thickened. The upper half of the billet is substantially cylindrical, the portion just below the cylindrical portion being conical, and carrying at its bot-tom a substantially disk-like flange 40 with a plane lower face 41. Near the top of the billet is aprojecting ring 42 which serves to keep the billet centered and out of eX- tensive surface contact with the cylinder 10, thus preventing sticking of the billet due to the capillary film of liquid which would otherwise result.

The dash pot cylinder 18 is secured to and carried by a coupling member 43 in turn supported by a horizontal plate 44, which also carries the depending closed chamber 45. A bore 46 connects the dash pot cylinder 18 with the interior of the chamber 45, and the stem or rod 13 passes freely through said bore. The lower surface of plate 44 serves as a valve seat for the valve disc 14 on said rod, and is also provided with another bore 47, both bores thus being closed when the valve disk 14 is elevated into contact with its seat. The bore 47 leads into tube 48 which connects at its upper end with `another bore 49 in the upper head 2, said bores 47 and 49, and tube 48, thus establishing communication from the interior of chamber 45 to the exterior of the pump near the top thereof, when the valve 14 is unseated. A bore 50 is provided in coupling member 43, and is in communication with the vertical tube 51, which in turn connects with a bore 52 in the upper head 2, which leads to the Huid outlet 53 of the pump. vA check valve 68 is provided in'this bore to preventdownward movement of the liquid.

The air inlet conduit 56 communicates through bore 57 in upper head 2 with the chamber 58, the upper wall of which comprises the flexible diaphragm 59. A cap 66' secures theA diaphragm in place, and is fastened to head 2 by screws 61. In cap 60 is a helical spring 62 which bears against disk 63 which in turn presses down the dia phragm 59. On its under surface the dia;

phragm carries a cupped disk 64 and below said disk is a valve ball 65 cooperating with a seat 66 at the end of bore 57.

The device operates as follows. 1 shows the parts in the at the end of the useful stroke. Valves 28, 65, 67 and 68 are all seat-ed, and valve 14 is unseated. The pressure in the casing 1 can find relief only by forcing the cylinder 10 and connected parts down, thus forcing the piston 12 down in the dash pot cylinder 18. This takes place quickly, because the liquid in the dash pot can escape through the relief conduit comprising bore 47, tube 48 and bore 49. A stream of liquid therefore leaves bore 49 with considerable velocity, but, by virtue of the position of the outlet of bore 49 at a distance from the foot valve, this stream does not stir up grit or sediment near the said foot valve, and this removes the objection to the corresponding relief passage 36 of the prior Patent No. 1,237,530, which discharged directly below the foot valve.

As stated, a rapid downward movement 0f cylinder 10 results, and the spring 31 suddenly overcomes the upward pressure which holds valve 67 to its seat, whereupon said valve 67 drops down in cylinder 10, leaving conduit 29 open, and permitting the air pressure in casing 1 to exhaust rapidly through said conduit and tube 55 to the atmosphere. Meanwhile, a slight leakage of air takes place into casing 1 through bore 71 in head 2 past Valve 65, which is intentionally made to have a small leakage. This leakage, however, fails to build up any appreciable pressure in the casing, because valve 67 is unseated and the casing therefore is open to the atmosphere'. Liquid, under its own gravitational pressure, now enters at the foot valve'5, and gradually fills the casing, lifting billet 28 and valve 67 as it rises, both said valves being floated by the liquid. As soon as the liquid level rises sufficiently, the springs 32 will raise the cylinder 10, and further rise of the liquid will seat the ball valve 67 on its seat in the end of conduit 29. Thereupon the leakage of air past valve 65 rapidly builds up pressure in the casing 1, because air can no vlonger escape from the casing. This pressure soon overcomes the force of the spring 62 in chamber 60, and forces the diaphragm 59 away from valve 65, which thereupon opens and allows the air to enter casing 1 rapidly. The resulting pressure forces the liquid to leave the casing Figure position they assume vthrough apertures 27, tube 24, apertures 23,

bore 50, conduit 51, past valve 68 in bore 52 and out by way of pipe 53 to the place -where the liquid is to be delivered.

The liquid continues to flow until its level sinks low enough in cylinder 10 to cause billet 28 to fall back to its seat, whereupon the llO Yso

above cycle of operations Ais repeated indefinitely as long as air and liquid are supplied.

In the prior Patent No. 1,237,530, a ball 2.0 was provided instead of the billet now used. This billet constitutes a very important improvementover the ball formerly employed. It is a very difficult and consequently expensive matter to produce a buoyant ball valve which is accurately spherical, as tins are difficult to avoid in molding such spheres. A sphere valve at best has an unsatisfactorily small area of contact with its seat and consequently it is diificult'to attain freedom from leakage. Even if the valve when new is perfect, it soon wears out of true and soon leals to a prohibitive extent, and requires replacement. Such replacement in a deep well pump is a matter of difficulty and expense, and may involve a shutdown of the pump for a considerable period. The billet has a large flat-bottom base which acts practically as would a dislr valve, having a large area of contact with its seat, and securely held to its seat by the pressure of the liquid, yet the billet as a whole is buoyant and self-seating, that is, it is just as certain to lind its seat as the sphere would be, because of its peculiar' shape and conn struction. Because of the large area of contact of the valve disc of the billet with its seat, it will wear for a very long time without developing leakage or other trouble, and because of the distributionV of weight of its parts it will float in its correct upright positiou, assisting materially in its proper and rapid engagement with its seat.

In the-pump disclosed in the 'prior patent, difficulty was encountered by the entry of grit into the dash pot, resulting in rapid wear' of the cup leathers as well as the dash pot cylinder itself. This difficulty has been avoided in the present case by the provision of the heavy felt washer 19 which effectively keeps grit out of the cylinder.

Another feature wherein lthe present invention is an advance over the patented pump resides in the hollow nut 22 which replaces the spider 38 of the patent. This nut serves all the functions of said spider, and is cheaper and easier to manufacture. The piston may be dismantled readily without toolsV by inserting` a rod through opposite holes 23 and thereby unscrewing the nut.

I claim:

1. In a pump of the character described,a billet comprising a'core, a covering of resilient material on said core, aresilient disk valve integral with the lower end of said resilient covering, and a guide member secured to the core.

2. In a pump of the character described,

a billet comprising a core, a covering of re silient material on said core, a resilient disk valve lntegral with the lower' end of said resilient covering, and a guide member secured to the core, said guide member comprising a conical head projecting from the center of the face of the disk valve.

8. In a pump of the character described, a billet comprising a core of wood, a covering of soft rubber completely surrounding saidV core, and a metallic guide member secured to the core and having a portion projecting beyond the rubber covering, the proportionate amounts of the various materials being so chosen that the whole billet has a density slightly less than that of the liquid with which it is to be used.

l. In a pump of the character described, a billet comprising a core, a covering of resilient material on said core and a resilient disk valve carried by one end of said billet.

5. In a pump of the character described, a billet comprising a core, a covering of resilient material on said core, and a resilient disk valve integral with one end of said covering.

6. In a pump of the character described, comprising a vertical body having an intake at its lower end, a dash pot, a relief passage leading from said dash pot to a point adja cent the upper end of the pump, and a valve controlling said relief passage.

7. In a pump of the character described, the lcombination with a hollow cylindrical guide memberof a billet, said billet being of less diameter than the diameter of the guide member and having a circumferen tially disposed projection, said projection being adapted to engage the inner surface of said cylindrical guide member and thereby maintain said billet in correct alignment.

8. In a pump of the character described, the combination with a primary hollow cylindrical guide member having a secondary concentrically disposed hollow guide member disposed at the base thereof of a billet, said billet being of less diameter than the diameter of the primary guide member, and having a guide member secured thereto, said guide member being adapted to engagethe secondary hollow guide member substan-Y tially as and for the purpose described.

9. In a pump of the character described,

the combination with a primary hollow cyi lindrical guide member having a secondary concentrically disposed hollow guide member disposed at the base thereof of a billet, said billet being of less diameter'than the diameter of the primary guide member and having a circumferentially disposed projection adjacent one end thereof, a guide member secured to the opposite end of said billet, said projection and said guide member being adapted to engage the primary and secondary hollow guide members respectively for the purpose of aligning said billet.

In testimony whereof I allixmy signature.V

JOHN L. LATTA. 

